This invention relates to esters, amides and N-substituted amides of 2-[N-(hydroxypiperidinoalkyl) and (hydroxypyrrolidinoalkyl)aminosulfonyl]-6-nitrobenzoic acids which are useful as sensitizers of hypoxic tumor cells to therapeutic radiation. It also relates to pharmaceutical formulations comprising one of such compounds and a non-toxic pharmaceutically acceptable carrier and to the use of an effective amount of said compounds which comprises administering an effective amount of such compound to patients in need of such radiation treatment.
At the present time, certain other unrelated compounds are in experimental clinical use as radiation sensitizers. However, these compounds--for example, metronidazol and misonidazole--suffer from the drawback that they also cause neurotoxicity which limits their usefulness. The compounds of the present invention are effective radiation sensitizers and are believed to have a more favorable therapeutic ratio.